I've been using skillbroken hashirama (+1auto, +passive) ever since the feature came out (4months now?). I can say right off the bat, go for 4*- you can get 15more frags from home interface for leveling him up to 20. His frags are way harder to come by than skill books- if you ever decide in the future you want his books, you c*ways buy them. +1 standard with a chance to immobile triggers in about 25% of even power fights. +2 on the other hand triggers very, very often, so if you dont have enough to make it +2, imo it just isnt worth even starting it. Passive seems good on paper, but there are hardly ever any instances it will be useful. Only thing is summon instance and gnw, but given the fact how fast ninjas die there they usually wont benefit from it lasting longer than 5 rounds. Also after won match, buffs are recasted. The only redeeming factor of this skillbook is that it isnt removed by Han, who in time will be less and less seen.

Personally if I had the choice again, I'd make mine +4 instead of getting those books. Usually it's better to keep him alive longer because of stat boost rather than have a chance to proc combo immobile on a target once every 4 fights.